An ignition system for a multiplecylinder engine which uses a battery as an ignition power supply is required to include a distributor which distributes a primary current to respective primary coil portions of ignition coils. Such an ignition system, however, has a disadvantage that the distributor tends to break down due to leakage of water into the distributor or other causes.
In order to eliminate such a disadvantage, there has been employed such as ignition system for a multicylinder engine that a magneto is used as an igniting power supply. In the prior art, this ignition system comprises a combination of ignition circuits provided individually for the respective cylinders of the engine. Therefore, the whole ignition system is large-sized and very complicated, which makes the ignition system expensive.